Answer:The ratio of the concentrations of 
and 
when the buffer has a pH of 7.02 is 0.69
Explanation:
The dissociation constant for formic acid = 
Concentration of HA= 0.5 mM
Concentration of = 0.1 mM
pH = 6.16
First we have to calculate the value of 
.
Using Henderson Hesselbach equation :
![pH=pK_a+\log \frac{[A^-}{[HA]}](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%20%5Cfrac%7B%5BA%5E-%7D%7B%5BHA%5D%7D)
Now put all the given values in this expression, we get:
![6.16=pK_a+\log (\frac{[0.1]}{0.5})](https://tex.z-dn.net/?f=6.16%3DpK_a%2B%5Clog%20%28%5Cfrac%7B%5B0.1%5D%7D%7B0.5%7D%29)
To calculate the ratio of the concentrations of and when the buffer has a pH of 7.02.
Using Henderson Hesselbach equation :
![7.02=6.86+\log \frac{[A^-]}{[HA]}](https://tex.z-dn.net/?f=7.02%3D6.86%2B%5Clog%20%5Cfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
![\frac{[A^-]}{[HA]}=1.44](https://tex.z-dn.net/?f=%5Cfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D%3D1.44)
![\frac{[HA]}{[A^-]}=0.69](https://tex.z-dn.net/?f=%5Cfrac%7B%5BHA%5D%7D%7B%5BA%5E-%5D%7D%3D0.69)
Thus the ratio of the concentrations of and when the buffer has a pH of 7.02 is 0.69
Answer:
Water molecules are polar and form strong hydrogen bonds.
Explanation:
Properties like high surface tension and boiling point are unique to water due to water's polar molecules. This allows water to form very strong hydrogen bonds and give it some different abilities.
D. The repressor is freed from the operator when lactose is present.
Think of a bacteria that comes into contact with some lactose sugar in milk. Normally it's not in milk, so the gene is repressed (prevented) from making the lac enzyme (which digests lactose). Now when it comes across some milk, it wants to make as much lac as possible to eat up all the lactose.
FYI: trp for tryptophan works the exact opposite with repressor blocking when trp IS PRESENT.
An adaptation is the definition of the first one in the fact of the first century of that period in the first period in auburn
<span>Blood flow to the skin increases when the
temperature of the body rises. When you are too hot, the blood vessels in your
skin expand (dilate) to carry the excess heat to your skin's surface. It helps
cool your body. </span>
